>>56484842I've played KANTOOOO more times than I can count. Mostly FRLG.
The E4 does in fact have a bit of a level jump, even in the originals, at which point you just spend your money and throw yourself at the E4 until your pokemon level enough to give it a real attempt. The gyms themselves however have a very fair level curve, provided you are actually fighting encounters and aren't making drastic skips between gyms (i.e. directly from Misty to Koga to Blane). You'll be fine even if you lightly skip around.
People criticize gen 2's level curve because it's normal for the first 3 gyms or so, then becomes a flat line, then it starts going back to normal in kanto, until later gyms where it actually curves too high because the wild pokemon are level 10 while the local trainers and gym are 45+. It's very strange and unwieldy.
It's not that it makes the game bad, it's just an existing issue.